The term “intermodal” refers to a manner of transporting cargo by way of ships, semi-trailer trucks and/or railways. Cargo containers used during intermodal transport have been standardized to facilitate international trade. Indeed, the cargo containers must pass the certification tests of the International Organization for Standardization (ISO) for durability if they are to be used for both domestic and international transport. The moat widely used ISO classification of container is the 1AA class. Such containers are 40 foot long, 8 foot in wide and 8.5 foot high and have lifting and stacking points at the tops of their four corners. As a result, cargo handling and transport equipment, such as cranes, trucks, trailers, railway cars, etc., have been built to accept containers having such fitments.
The weight capacity of a cargo container is often limited by the weight of the container itself. In other words, if the container is made lighter, it may be used to carry a heavier cargo load. As a result, collapsible intermodal flat racks, such as the flat racks offered by Domino Flatracks (Clive-Smith Cowley Ltd) of the United Kingdom and illustrated in published UK Patent Application GB 2376014 and U.S. Pat. No. 5,275,301, both to Clive-Smith, have been developed. Such collapsible intermodal flat racks omit the container side and end walls and top and instead feature a floor or cargo deck that features arches that are pivotally attached to move between an upright use position, a folded stored position and an expanded position for placing a load on the cargo deck from above (such as by crane).
In addition to offering a weight savings, such collapsible intermodal flat racks permit the cargo deck to be longer than 40 foot as the arches feature lifting and stacking fitments and are positioned inward from the flat rack ends and 40 foot apart to permit handing by standardized equipment.
In addition, the collapsible intermodal flat racks permit the flat racks, when in the collapsed storage configuration, to be stacked for transport. As a result, the necessity of returning an empty cargo container is avoided. Instead, a number of collapsed intermodal flat racks may be transported in the same space required to return a single empty non-collapsible ISO class 1AA container.
While the collapsible intermodal flat racks of Clive-Smith offer the above advantages, changing the configuration of the arches or vertical uprights is laborious in that they must be directly lifted and handled and manually moved between the use, storage and expanded load positions. One solution to this problem is offered in U.S. Pat. No. 7,823,739 to Sadkin et al., where end walls of a collapsible shipping container are moved by a support or lever on each side having one end pivotally attached to the end wall, and a second end that moves within a track formed on the side of the cargo deck beam. A hydraulic or electric motor is positioned under the deck and moves the ends of the levers positioned within the tracks so that they travel towards the longitudinal center of die cargo deck thus causing the end walls to fold. The disadvantage of this approach, however, is that a source of power, either onboard or off is required. Furthermore, the motor mechanism adds to the cost and complexity.